In an effort to increase lift or reduce drag and/or noise levels of wind turbine blades, devices are often used at the trailing edge of wind turbine blades to adjust or regulate the flow in the wake of the wind turbine blade. Such devices may include serrations, bristles, or acoustic flaps. These devices operate through the modification of the flow properties, and/or through the adsorption of energy from the airflow over the blades through mechanical bending of the devices under action of the wind.
One issue with such devices, however, is that the bending of such devices during operation of the wind turbine may result in flow separation is the region of the devices, due to the relatively high angle of attack in the region of the bent devices. Such flow separation can result in an increased drag effect for the wind turbine blade, and/or increased operational noise of the wind turbine blade.
It is an object of the invention to provide a solution for a wind turbine blade wherein flow separation over trailing edge devices is prevented during periods of bending of the trailing edge devices, without impacting on normal operation of the wind turbine blade.